<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            text-decoration: none;
        }

        .top {
            width: 500px;
            margin: 0 auto;
            height: 400px;
            border: 2px solid gray;
            background-repeat: no-repeat;
        }

        img {
            width: 500px;
            height: 400px;
        }

        .inner1,
        .inner2,
        .inner3 {
            position: absolute;
            margin-top: 0;
            display: block;
        }

        .ul {
            width: 150px;
            height: 15px;
            font-size: 10px;
            line-height: 15px;
            text-align: center;
            margin: 0 auto;

        }

        .first {
            display: inline-block;
            width: 15px;
            height: 15px;
            border: 1px solid;
            background-color: lightblue;
            border-radius: 50%;
            margin-right: 15px;
        }

        .first:hover {
            background-color: red;
        }
    </style>
</head>

<body>
    <div class="top">
        <div class="inner1">
            <img src="img/1.jpg">
        </div>
        <div class="inner2">
            <img src="img/2.jpg">
        </div>
        <div class="inner3">
            <img src="img/3.jpg">
        </div>

    </div>
    <div class="ul">
        <ul>
            <li class="first one">1</li>
            <li class="first two">2</li>
            <li class="first three">3</li>
        </ul>
    </div>
</body>

</html>